Ed25519 Sign / Verify
Sign messages with Ed25519 private keys and verify signatures with public keys directly in your browser.
Sign Message
Enter either the 32-byte seed or the 64-byte seed+public key (hex/Base64). When a 64-byte value is provided we automatically use the first 32 bytes as the private seed for signing.
Verify Signature
Paste a public key and signature (Base64/Hex) to ensure a message’s integrity.
Waiting for input...
Ed25519 Signatures
Ed25519 is a modern, deterministic signature algorithm that trades heavyweight modular arithmetic for fast field operations and uses small keys (32-byte public keys, 64-byte private keys).
Why it matters
- Deterministic signatures remove reliance on random nonces, eliminating a common failure mode.
- Small key and signature sizes suit constrained environments (IoT, mobile).
- Ed25519 is built for high performance despite strong security guarantees.
Safety note: Keep private keys (seeds) private, verify signatures before trusting messages, and never copy keys into shared machines.
Seed guidance: You can paste either a 32-byte seed or the 64-byte seed+public key (hex/Base64). For the longer form the tool automatically uses the first 32 bytes as the signing seed.